What does a higher film density indicate in terms of tissue density on a radiograph?

A higher film density on a radiograph indicates a greater amount of radiation absorption by the tissues being imaged. When tissues are denser, they absorb more radiation, resulting in a darker area (higher density) on the film. This is because denser tissues, such as bone or tumors, will reflect and absorb more of the x-ray photons compared to less dense tissues, leading to a more pronounced appearance on the film. Thus, interpreting film density allows radiologists and medical professionals to infer information about the underlying tissue composition and density, aiding in diagnostics and treatment planning.